Improvement in devices for molding dovetails



AMO NL. F INCH. Improvement in Devices for Mold Ddvetaiis.

nted April. 2,, 1872;.

ing

Pate

PATENT OFFICE.

AMON L. FINOH, or sme SING, NEW YORK.

IMPROVEMENT IN DEVICES FOR MOLDING DOVETAILS.

Specification forming part of Letters Patent No. 125,186, dated April 2,1872.

declared to be a correct description of the same.

This invention is for molding dovetails in the sand, so as to cast thedovetailed lugs employed for holding stove-legs to the bottom plate ofstoves, and similar articles.

Prints have been made in the sand to form dovetails by means of lugsmade to move toward each other; but in this case thesand remainingbetween the lugs is compressed and liable to be displaced, and thedistance be tween one lug and the other will vary in consequence of themovement given to the lugs not being positive.

My invention is made to remedy these difficulties; and consists in ahead with a print or punch sliding at an inclination and in line withthe face of the dovetail; thereby the dis tance between the faces of thedovetail will be uniform, and the sand will be driven downwardly awayfrom the surface of the mold; thereby that surface will not be injuredor the sand loosened between the dovetail lugs.

In the drawing, Figure 1 is a section of the head and dovetail-prints,and Fig. 2 is an inverted plan of the same. Fig. 3 is a section of thehead with the sliding punch for completing the dovetail, and Fig. 4.shows the lugs upon the pattern that partially form the dovetailcavities ready for the reception of the head shown in Fig. 3.

The head a has openings through it at an inclination for the receptionof the punch or print I), which slides upon the line of the face of thedovetail. In Figs. 1 and 2 the sliding portion 1) is a complete print,the end thereof being of the size and shape required for the dovetaillug. The head a has two of these prints, 1), which, in a normalcondition, are held by the springs c in the position shown in Fig. 1 bydotted lines, the ends of the prints being within the head, so that theunder face thereof can be laid upon the sand mold in the proper positionand the prints be driven down into the sand by pressure, the distancebeing determined by the pins 6 or otherwise. The springs o draw up theprints so that the head a. and parts may be lifted off. In this mannervery perfect dovetails are molded, and with great rapidity. In caseswhere the dovetail is larger, or it is desired to have lugs upon thepattern to determine where the dovetail mech anism shall be applied tocomplete the mold, the lugs 11 i are made upon the pattern k, and theselift out of the sand freely, leaving cavities, into which theguide-blocks o o of the head a are placed, and then the punch b ispushed down through the mortises in a, as seen in Fig. 3, and gives shape to the face of the dovetail cavity. This punch b is applied to firstone side and then the other, and a stop upon the surface of the print orpunch b, or at the edges thereof, determines the point to which it is tobe impressed to perfect the dovetail mold.

I claim as my invention- 1. The guide-blocks 0 o of the head a, adjacentto the mortises through said head a, for the punch b, which forms theinclined faces of the dovetail, as specified.

2.'Thehead a, with diagonal mortises through it, in combination with thetwo inclined punches b, and springs c for withdrawing the punches fromthe sand, as set forth.

Signed by me this 5th day of December, A. D. 1871.

Witnesses: A. L. FINCH.

Gno. T. PINGKNEY, CHAS. H. SMITH.

